GPR_$INQ_VIS_LIST                 GPR Calls                  GPR_$INQ_VIS_LIST


NAME
     gpr_$inq_vis_list - returns a list of the visible sections of an obscured
     window.

FORMAT
     gpr_$inq_vis_list (slots_available, slots_total, vis_list, status)

DESCRIPTION
     This routine returns a list of the visible sections of an obscured win-
     dow.

     If the display has been acquired but the target window is obscured, pro-
     grams can call gpr_$inq_vis_list to locate any visible sections of the
     window.

     If the target window is visible, this routine returns a base of (0,0) and
     the size of the entire window.

     gpr_$inq_vis_list implicitly releases and reacquires the display in order
     to communicate with the Display Manager.

   Input Parameters
     slots_available
          Size of the array of visible window sections.  This is a 2-byte
          integer, which is the maximum number of visible rectangles that can
          be returned.  If you want to list all existing sections, you must
          specify a number that is greater than or equal to the number
          returned in the slots_total argument (see output parameters).

   Output Parameters
     slots_total
          Number of existing visible rectangles.  This is a 2-byte integer.
          If this value is greater than the slots_available parameter, then
          only the number of rectangles specified in slots_available is
          returned.

     vis_list
          List of visible window sections.  This is an array in gpr_$window_t
          format.  This data type is eight bytes long.  There is no set limit
          to the number of visible regions that may be returned.

     status
          Completion status, in status_$t format.

SEE ALSO
     gpr_$set_clip_window, gpr_$set_mult_clip_window.

NOTES
     If the window is obscured, the application should call
     gpr_$set_clip_window once for each rectangle returned by
     gpr_$inq_vis_list before making calls to drawing routines.  Clipping is
     to rectangles only.  The GPR software will not perform clipping automati-
     cally.